2aiq

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spinqualitylabelsall models 2aiq, resolution 1.54Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image

Crystal structure of benzamidine-inhibited protein C activator from the venom of copperhead snake Agkistrodon contortrix contortrix

Overview

Protein C activation initiated by the thrombin-thrombomodulin complex forms the major physiological anticoagulant pathway. Agkistrodon contortrix contortrix protein C activator, a glycosylated single-chain serine proteinase, activates protein C without relying on thrombomodulin. The crystal structures of native and inhibited Agkistrodon contortrix contortrix protein C activator determined at 1.65 and 1.54 A resolutions, respectively, indicate the pivotal roles played by the positively charged belt and the strategic positioning of the three carbohydrate moieties surrounding the catalytic site in protein C recognition, binding, and activation. Structural changes in the benzamidine-inhibited enzyme suggest a probable function in allosteric regulation for the anion-binding site located in the C-terminal extension, which is fully conserved in snake venom serine proteinases, that preferentially binds Cl(1-) instead of SO(4)(2-).

About this Structure

2AIQ is a Single protein structure of sequence from Agkistrodon contortrix contortrix with , , , , , and as ligands. Active as Venombin A, with EC number 3.4.21.74 Full crystallographic information is available from OCA.

Reference

Thrombomodulin-independent activation of protein C and specificity of hemostatically active snake venom serine proteinases: crystal structures of native and inhibited Agkistrodon contortrix contortrix protein C activator., Murakami MT, Arni RK, J Biol Chem. 2005 Nov 25;280(47):39309-15. Epub 2005 Sep 14. PMID:16162508

Page seeded by OCA on Thu Feb 21 16:27:49 2008